downregulation of CSN4 in Arabidopsis and in tobacco cells leads to delayed G1/S transition comparable to that observed when TCTP is downregulated. Loss-of-function of AtTCTP leads to increased fraction of deneddylated CUL1, suggesting that AtTCTP interferes negatively with COP9 function. Similar defects in cell proliferation and CUL1 neddylation status were observed in Drosophila knockdown for dCSN4 or dTCTP
Loss of AtCEP2, but not AtCEP1 resulted in shorter primary roots due to a decrease in cell length in the lateral root (LR) cap and impairs extension of primary root epidermis. AtCEP1 and AtCEP2 are expressed in root epidermis cells that are separated for LR emergence. Loss of AtCEP1 or AtCEP2 caused delayed emergence of LR primordia.
Increased embryo and seed size in krp4/6/7 mutants results from seed abortion, presumably reducing resource competition, and that seed size differences contribute to the phenotype of several large-leaf mutants. Results provide a new understanding of the role of cell cycle regulation in leaf development and highlight the contribution of the embryo to the development of leaves after germination in general. [Krp6]
The appearance of RAD54 foci was dependent on the ATAXIA-TELANGIECTASIA MUTATED-SUPPRESSOR OF GAMMA RESPONSE 1 pathway, and RAD54 foci were co-localized with gammaH2AX signals. Laser irradiation of a subnuclear area demonstrated that in living cells RAD54 was specifically accumulated at the damaged site. In addition, the formation of RAD54 foci showed specificity for cell type and region. We conclude that RAD54 foci co...
MADS-box protein AGL80 was verified as a transcriptional repressor that directly suppresses the expression of accessory cell-specific genes to specify the central cell in Arabidopsis. AGL80 acts as a transcription repressor through the EAR motif to repress the expression of MYB98. Further genetic rescue and phylogenetic assay of the AGL80 orthologs revealed a possible conserved mechanism in the Brassicaceae family.
Mitochondrial perturbations related to a defect in complex I in the Arabidopsis thaliana frostbite1 (fro1) mutant, carrying a point mutation in the 8-kD Fe-S subunit of NDUFS4 protein, alter aspects of fundamental carbon metabolism, which is manifested as stunted growth. The responses of fro1 plants to NH treatment were consistent with the inhibition of a form of programmed cell death.
UPEX1 and IRX9L function in exine patterning in developing microspores by modulating the synthesis or modification of components of the primexine wall layer. Data support a model in which xylan and AGP cell wall components synthesized in tapetum are incorporated into the primexine wall and play roles in primexine development and anchoring of sporopollenin to the microspore surface early in microspore development. [IRX9L]
UPEX1 and IRX9L function in exine patterning in developing microspores by modulating the synthesis or modification of components of the primexine wall layer. Data support a model in which xylan and AGP cell wall components synthesized in tapetum are incorporated into the primexine wall and play roles in primexine development and anchoring of sporopollenin to the microspore surface early in microspore development. [UPEX1]
Increased embryo and seed size in krp4/6/7 mutants results from seed abortion, presumably reducing resource competition, and that seed size differences contribute to the phenotype of several large-leaf mutants. Results provide a new understanding of the role of cell cycle regulation in leaf development and highlight the contribution of the embryo to the development of leaves after germination in general. [Krp7]
PIN1 phosphorylation at S1-S4 was detected in situ using phosphosite-specific antibodies. Pin 1 phosphorylation at phosphosites at the basal as well as the apical plasma membrane in different root cell types, in embryos, and shoot apical meristems followed the predominant PIN1 distribution but was not restricted to specific polar sides of cells. Different protein kinases or trafficking mechanisms are involved.